JP4847401B2 - Mobile robot drive unit - Google Patents

Description

  The present invention relates to a drive device for a mobile robot, and more particularly to a drive device for a mobile robot that efficiently supplies a drive voltage to an electric motor disposed at a joint.

A mobile robot normally operates by being supplied with a drive voltage from an installed battery (power supply) to an actuator such as an electric motor. As an example, the technique described in Patent Document 1 can be cited. In the technique described in Patent Literature 1, two leg links connected to the base via the hip joint and connected via the knee joint, an electric motor arranged at these joints, and the base In a legged mobile robot drive device having a battery (power source) disposed in the vehicle and a drive circuit that drives the electric motor by supplying a voltage supplied from the battery through the power line, the remaining capacity of the battery is reduced When it is judged that the situation is likely to fall, it operates to lower the center of gravity.
JP-A-11-48170

  In the above-described prior art, since the power line from the battery crosses the joint depending on the electric motor, it is desirable to drive the electric motor at a low voltage in consideration of the case where the power line is disconnected at the joint portion and the electric leakage occurs. . However, in order to move at high speed, it is necessary to drive the electric motor with a high voltage to increase the rotation speed, and thus the requirements of both are contradictory.

  Accordingly, the object of the present invention is to eliminate the above-mentioned disadvantages of the prior art, satisfy both the low voltage requirement considering safety and the high voltage requirement for high speed movement, and thus efficiently supply the voltage. To provide a driving device for a mobile robot.

In order to solve the above-described problem, in claim 1 , the invention includes a base, a thigh link connected to the base via a hip joint, and a crus link connected to the thigh link via a knee joint. and a plurality of legs, front Symbol a first electric motor for driving the thigh link in the traveling direction, and a second electric motor for driving the front Symbol lower leg link in the traveling direction, other than the thigh link and the crus link A power source disposed at a site, a power line connecting the power source and the first and second electric motors, and a voltage supplied from the power source through the power line in response to an energization command. In a mobile robot drive device comprising at least a drive circuit for supplying and driving a motor, a booster for boosting a drive voltage supplied to the first and second electric motors, and the boost according to a moving situation Ascension of vessel Together and a step-up control means for controlling the operation, the first and the second electric motor and the booster and prior to hear dynamic circuits as configured to place said thigh link.

The mobile robot drive device according to claim 2 is configured such that the booster is inserted in the power line, and a bypass path is provided in the power line to bypass the booster.

In the mobile robot driving apparatus according to claim 3 , the boost control means is configured to control a boost operation of the booster by searching a preset table value in accordance with the movement state.

In the mobile robot drive device according to a fourth aspect , the boost control means monitors the output voltage of the booster and stops the boost operation when the boost voltage is not boosted to a predetermined voltage.

The mobile robot driving apparatus according to claim 5 includes a temperature sensor disposed in at least one of the booster and a driving circuit, and the boost control means is detected via the temperature sensor. When the temperature is equal to or higher than a predetermined temperature, the boosting operation is stopped.

The mobile robot drive device according to claim 6 includes feedback control means for performing feedback control of the drive current to a target value, and the feedback control means performs the feedback control according to the boost operation of the boost control means. It was configured to change the gain.

According to claim 1 , the apparatus includes a plurality of legs including a thigh link connected to the base body via a hip joint and a lower leg link connected to the thigh link via a knee joint, In a drive device for a legged mobile robot comprising at least a drive circuit that supplies and drives a first and second electric motors driven in the traveling direction by supplying a voltage supplied from a power source through a power line in accordance with an energization command. A booster that boosts the drive voltage supplied to the first and second electric motors, and a boosting control unit that controls the boosting operation of the booster according to the movement state ; and the first and second electric motors; since the booster and driving circuit is composed as to place the thigh link, it is possible to satisfy both the high voltage requirements for low voltage requirements and high speed mobile considering safety, thus effectively voltage Supply Door can be.

In other words, by providing a booster on the same link as the drive circuit, the transmission voltage of the power line can be kept low, and when the power line connecting the power source and the electric motor straddles the joint, even if the joint part breaks and leaks, Inconvenience does not occur. On the other hand, when a high voltage is required, it is possible to cope with high-speed movement by boosting and supplying the voltage with a booster, and thus the voltage can be supplied efficiently. Further, the arrangement of the booster is limited to the electric motor that drives the thigh link or the like in the traveling direction, in other words, the one that requires a high voltage, and arranges them on the same link. Since it comprised, a voltage can be supplied more efficiently. In addition, since the booster control means for controlling the boosting operation of the booster according to the movement state is provided, the necessary voltage can be supplied without excess or deficiency, and the voltage can be supplied more efficiently.

In the mobile robot drive device according to the second aspect , the booster is inserted in the power line, and the power line is provided with a bypass path that bypasses the booster. While there is an inconvenience that requires a backflow prevention diode or the like, power loss can be reduced as compared with the case of using a booster.

In the mobile robot drive device according to the third aspect , the boost control means is configured to search the table value set in advance according to the movement state and control the boost operation of the booster. In addition to the effect, it becomes easy to supply the necessary voltage without excess or deficiency, and the voltage can be supplied more efficiently.

In the mobile robot drive apparatus according to claim 4 , the boost control means monitors the output voltage of the booster and stops the boost operation when the boost voltage is not boosted to a predetermined voltage. In addition, a failure can be detected simply by monitoring the output of the booster, and necessary measures such as stopping the movement can be taken.

The mobile robot drive device according to claim 5 includes a temperature sensor disposed in at least one of the booster and the drive circuit, and the boost control means has a predetermined temperature detected via the temperature sensor. Since the boosting operation is stopped when the temperature is higher than the temperature, in addition to the above-described effects, a failure can be detected through the temperature and necessary measures such as stopping the movement can be taken.

The mobile robot driving apparatus according to claim 6 includes feedback control means for feedback-controlling the drive current to the target value, and the feedback control means increases the feedback control gain according to the boosting operation of the boosting control means. Since the configuration is changed, the electric motor can be reliably driven at a necessary number of rotations in addition to the above-described effects.

  The best mode for carrying out a mobile robot drive device according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a front view of a mobile robot targeted by a mobile robot drive apparatus according to a first embodiment of the present invention, and FIG. 2 is a side view of the robot shown in FIG. As a mobile robot, a two legged mobile robot is taken as an example.

  As shown in FIG. 1, a legged mobile robot (hereinafter simply referred to as a “robot”) 10 has a plurality of legs, that is, two left and right leg portions 12L and 12R (the left side is L, the right side is R, and so on). Is provided. The leg portions 12 </ b> L and 12 </ b> R are connected to the lower portion of the base body (upper body) 14. A head portion 16 is connected to the upper portion of the base body 14, and a plurality of arm portions 20 </ b> L and 20 </ b> R are connected to the side portions. Hands (end effectors) 22L and 22R are connected to the tips of the left and right arm portions 20L and 20R, respectively.

  As shown in FIG. 2, a storage portion 14 a is provided at the back of the base body 14, and a central controller 24 and a power supply controller 26 are accommodated therein, and a battery (power source) 28 is provided inside the base body 14. Etc. are accommodated.

  FIG. 3 is an explanatory diagram showing the robot 10 shown in FIG. 1 as a skeleton. Hereinafter, the internal structure of the robot 10 will be described focusing on the joints with reference to FIG. Since the illustrated robot 10 is bilaterally symmetric, L and R are not described below.

  The left and right legs 12 include a thigh link 30, a crus link 32, and a foot 34, respectively. The thigh link 30 is connected to the base body 14 via a hip joint. In FIG. 3, the base 14 is simply shown as a base link 36. The hip joint has an electric motor (referred to as “1Z motor”) 40 having a rotation axis around the Z axis (yaw axis) and a rotation axis around the Y axis (pitch axis, specifically, the left-right direction of the robot 10). An electric motor (referred to as “1Y motor”) 42 and an electric motor (referred to as “1X motor”) 44 having a rotation axis around the X axis (roll axis, specifically, the front-rear direction of the robot 10). It has 3 degrees of freedom.

  An electric motor (referred to as “2Y motor”) 46 having a rotation axis around the Y axis is disposed at the knee joint and has one degree of freedom. An electric motor (referred to as “3Y motor”) 48 having a rotation axis around the Y axis and an electric motor (referred to as “3X motor”) 50 having a rotation axis around the X axis are arranged at the ankle joint, and has two degrees of freedom. . The thigh link 30 and the lower leg link 32 are connected via a knee joint, and the lower leg link 32 and the foot 34 are connected via an ankle joint. The leg portion 12 is individually driven by twelve rotating shafts by twelve electric motors arranged at appropriate positions of the base body 14 and the leg portion 12.

  The left and right arm portions 20 include an upper arm link 52 and a lower arm link 54, respectively. The upper arm link 52 is connected to the base body 14 through a shoulder joint. The upper arm link 52 and the lower arm link 54 are connected via an elbow joint, and the lower arm link 54 and the hand 22 are connected via a wrist joint.

  An electric motor 56 having a rotation axis around the Y axis, an electric motor 58 having a rotation axis around the X axis, and an electric motor 60 having a rotation axis around the Z axis are arranged at the shoulder joint and have three degrees of freedom. An electric motor 62 having a rotation axis around the Y axis is arranged at the elbow joint and has one degree of freedom. An electric motor 64 having a rotation axis around the Z axis, an electric motor 66 having a rotation axis around the Y axis, and an electric motor 68 having a rotation axis around the X axis are arranged at the wrist joint and have three degrees of freedom. Similarly to the leg portion 12, the arm portion 20 is also individually driven with 14 rotating shafts by 14 electric motors arranged at appropriate positions of the base body 14 and the arm portion 20.

  The head 16 is connected to the base 14 via a neck joint and has two degrees of freedom. An electric motor 72 having a rotation axis around the Z axis and an electric motor 74 having a rotation axis around the Y axis are arranged at the neck joint, and have two degrees of freedom. The head 16 is also individually driven by two electric motors.

  A six-axis force sensor 76 is attached to each of the left and right leg portions 12, and the three-direction components Fx, Fy, Fz of the floor reaction force acting on the leg portion 12 from the floor surface and the three-direction components Mx, My, Mz of the moment are applied. 6-axis force sensors 78 of the same kind are attached to the left and right arm portions 20 between the hand 22 and the wrist joint, and the three-direction components Fx, Fy, Fz of the external force acting on the arm portion 20 are output. And a signal indicating the three-direction components Mx, My, and Mz of the moment.

  The base 14 has an inclinometer 80 composed of three acceleration sensors that generate an output indicating acceleration in the X, Y, and Z axis directions and three vibration gyros that generate an output indicating angular velocity about the X, Y, and Z axes. Be placed.

  The head 16 is provided with two CCD cameras 82 for outputting an image obtained by photographing the environment around the robot 10 in stereo, and an audio input / output device 84 including a microphone 84a and a speaker 84b. It is done.

  A rotary encoder (not shown) is disposed in each of the electric motors 40 and 42 constituting the leg portion 12 and the arm portion 20, and outputs a signal corresponding to the rotation angle, that is, the joint angle. The electric motors 40, 42, etc. are DC brushless motors, for example.

  Outputs from the above-described sensors and the like are input to the central controller 24. The central controller 24 is composed of a CPU unit, and controls the operation of an electric motor such as the 1Z motor 40 of the leg 12 to drive the leg 12 to move the robot 10, and the electric motor 56 of the arm 20 and the like. The arm portion 20 is driven by controlling the movement of the head 16 and the movement of the electric motor 72 of the head 16 is controlled to adjust the orientation of the head 16.

  FIG. 4 is a block diagram showing supply of drive voltage from the battery 28 to an electric motor such as a 1Z motor (electric motor) 40. In the figure, illustration of the configuration of the arm 20 is omitted, and only one of the legs 12 is shown.

  As shown in the drawing, six electric motors such as a battery 28 and a 1Z motor 40 are connected via a power line controller 26 and three motor drivers (drive circuits) 92, more specifically 92a, 92b, and 92c. Connected. The central controller 24 is communicatively connected to the power supply controller 26 via a signal line 94 and is communicably connected to three motor drivers 92 via a signal line 96. The three motor drivers 92 also have a CPU inside, and control the operation of the two electric motors connected.

  Of the three motor drivers 92, a booster 98, more specifically 98a, 98b, is inserted in each of the power lines 90 connected to 92b, 92c. The booster 98a and the motor driver 92b, and the booster 98b and the motor driver 92c are connected via the signal line 100 so as to be capable of bidirectional communication.

  The battery 28 outputs a relatively low predetermined voltage Vm [V]. The predetermined voltage Vm output from the battery 28 is sent to the power line 90 via the power supply controller 26, and the power line 90 serves as a control power source for a motor driver 92 (and a temperature sensor described later) and an electric motor such as a 1Z motor 40. The motor is supplied as drive power. More precisely, the power line 90 branches halfway, and the control power supply is sent to the three motor drivers 92 and the like as the operation power supply via the branch line 90a.

  With the configuration shown in the figure, a predetermined voltage Vm is supplied as it is as a drive voltage to the 1Z motor 40 and 1X motor 44 via the motor driver 92a, while the 1Y motor 42, 2Y motor 46 and 3Y are supplied via the motor drivers 92b and 92c. The motor 48 and the 3X motor 50 are supplied with a predetermined voltage Vm or a voltage obtained by boosting the predetermined voltage Vm up to four times (4 Vm) by the booster 98 as a drive voltage.

  The signal line 96 is made of ARCNET (RS485-based communication) or Ethernet (registered trademark), and forms an in-vivo network. The output of the six-axis force sensor 76 is sent to the central controller 24 through a signal line 96. Further, the temperature sensors 102 are respectively arranged in the three motor drivers 92 and the two boosters 98, and output indicating the temperature of the arrangement part is generated. The output of the temperature sensor 102 is also sent to the central controller 24 and the motor driver 92 via a signal line 96 (not shown). Although not shown, the output of the rotary encoder arranged in the 1Z motor 40 and the like is also sent to the central controller 24 and the motor driver 92 via the signal line 96.

  As described above, the central controller 24 controls the operation of the 1Z motor 40 and the like of the leg 12 to drive the leg 12. That is, the central controller 24 sends a position / speed / current (torque) control command for each electric motor to the motor driver 92 based on an operation (walking) mode determined from a preset gait. Is transmitted from the motor driver 92 to the central controller 24. In addition, information such as temperature, abnormality, and a set value unique to the motor driver 92 is transmitted and received between the central controller 24 and the motor driver 92.

  Similarly, between the central controller 24 and the power supply controller 26, a power control command, information such as voltage / current, and various information such as temperature / abnormality / set value are transmitted / received via the signal line 94. 16, power control including power distribution to the arm 20 and the leg 12 is executed.

  FIG. 5 is a side view of the robot 10 similar to FIG. 2, specifically showing the arrangement of the motor driver 92 and the like shown in FIG. 4 in the robot 10.

  As shown in the figure, the central controller 24 and the power supply controller 26 are housed in the storage portion 14a, and the battery 28 is disposed inside the base 14, so that the power line 90 and the signal line (in-body network) 96 are connected to the hip joint and knee. It is stretched around the thigh link 30 and the lower thigh link 32 across the joint. The power line 90 is gently wired in the joint portion in consideration of the movement of the joint.

  The motor driver 92a is disposed on the base body 14, while the 1Z motor 40 and the 1X motor 44 are disposed on the thigh link 30, and therefore they are not disposed on the same link. On the other hand, the motor driver 92b, the 1Y motor 42, the 2Y motor 46, and the booster 98a are disposed on the same link (thigh link 30). In addition, the motor driver 92c, the 3Y motor 48, the 3X motor 50, and the booster 98b are disposed on the same link (crus link 32).

  More specifically, the 1Y motor 42 that drives the thigh link 30 in the traveling direction, the 2Y motor 46 that drives the crus link 32 in the traveling direction, the motor driver 92b, and the booster 98a are the same link ( It is arranged on the thigh link 30). Further, the 3Y motor 48 that drives the foot 34 in the traveling direction, the 3X motor 50 that drives in the left-right direction orthogonal to the traveling direction, the motor driver 92c, and the booster 98b thereof are also the same link (crus link 32). Placed in.

  Here, the problem of the present application will be described. FIG. 17 is a block diagram similar to FIG. 4 showing supply of drive voltage from the battery 28 to the 1Z motor 40 and the like used in the technique described in Patent Document 1.

  In the case of the configuration shown in FIG. 17, a high voltage obtained by multiplying the predetermined voltage Vm several times from the battery 28 through the power line 90 is supplied to the electric motor such as the 1Z motor 40. There is a possibility that 90 is disconnected and exposed. Therefore, in consideration of safety, it is desirable to supply power to the motor at a low voltage. When the robot 10 is in an upright state or does not operate at a high speed, it can be operated even to a certain low voltage (for example, a value (2 Vm) that is about twice the predetermined voltage).

  However, in order for the robot 10 to walk at high speed, it is necessary to increase the number of revolutions of the electric motor. Therefore, it is necessary to increase the voltage from the viewpoint of the size and efficiency of the electric motor. It was difficult to lower. In other words, low voltage considering safety and high voltage for high-speed walking are contradictory in design. In this specification, “high-speed walking” is used to include not only walking motion but also traveling motion.

The configurations shown in FIGS. 4 and 5 solve the problem. In addition to the configuration shown in FIG. 17, boosters 98a and 98b are inserted in front of the motor drivers 92b and 92c, and the booster 98a and the motor driver are inserted. The 92b and the 1Y motor 42 are arranged in the same link so that the power line 90 connecting them does not straddle the joint. However, 1Z motor 40 and 1X motor 44 is not particularly requiring high-speed rotation, since the power line 90 between the motor driver 92a crosses the hip joint, to the motor driver 92a is not arranged booster 98 and did.

  The motor drivers 92b and 92c turn off the boosters 98a and 98b when standing upright or walking at a low speed. On the other hand, at the time of high-speed walking operation, information on the high-speed walking (operation) mode is sent from the central controller 24 to the motor drivers 92b and 92c via the signal line (in-body network) 96, and the motor drivers 92b and 92c receiving this information A drive voltage control signal is sent through the line 100 to turn on the boosters 98a and 98b.

  As a result, high-voltage driving power is supplied to the motor drivers 92b and 92c downstream of the boosters 98a and 98b that are turned on, and the motor drivers 92a and 92b receive the operation mode received from the central controller 24 via the signal line 96. The desired motor speed is obtained by changing the setting to the current feedback gain corresponding to.

  High speed walking means an operation mode in which the robot 10 walks at a speed exceeding about 1.8 km / h, and low speed walking means an operation mode in which the robot 10 walks at a lower speed. In low-speed walking, the rotation speed of any electric motor is low even during the swing leg period, but in high-speed walking, the 1Y motor 42 and the 2Y motor 46 are required to rotate at high speed during the swing leg period. Therefore, as described with reference to FIG. 5, a booster 98 is provided at least for those electric motors, and the motor driver 92 is arranged on the same link.

  Next, the control of the motor driver 92 when the drive voltage changes will be described. The motor driver 92 changes the setting to the current feedback gain corresponding to the high-speed / low-speed operation mode, so that the rotation speed required for the electric motor is changed. Is realized. FIG. 6 shows a feedback loop for motor control.

  A DC brushless motor such as the 1Z motor 40 is generally feedback controlled for position, speed, and current, as shown in FIG. The current feedback gain Ki, more specifically, the proportional gain Kip and the integral gain Kii represent the magnitude of the feedback amount of the loop that controls the current flowing to the electric motor inside the position feedback loop and the speed feedback loop.

The energy of the electric motor is torque × number of rotations, the torque is proportional to the current, and the number of rotations is proportional to the voltage. If the energy is the same, the voltage and current are in an inversely proportional relationship, so the current is suppressed by the rate of voltage increase. That is, by reflecting the switching of the drive voltage in the current feedback gain as shown in the following equation, the desired operation can be realized even if the current flowing through the electric motor is changed and the voltage is changed.
Ki = C / V (Ki: current feedback gain, V: drive voltage, C: constant)

  Thus, to maintain the operating characteristics of the electric motor against voltage fluctuations, adjusting the current feedback gain is the simplest and most reasonable method. Further, the feedback gain must be a current gain, and cannot be realized with a position gain or a speed gain.

  FIG. 7 is a flowchart showing the operation of the mobile robot driving apparatus according to this embodiment. The illustrated program is executed by the central controller 24.

  FIG. 8 is an explanatory diagram showing characteristics such as drive voltage set by the processing of FIG. The values shown in FIG. 8 are values for the 2Y motor 46, but the same applies to the 1Y motor 42. As shown in FIG. 8, in the process shown in FIG. 7, the drive voltage remains at the predetermined voltage Vm except during walking, but after starting walking, it is doubled (2 Vm) or four times (4 Vm) depending on the walking speed. ) Increase the pressure.

  The current feedback gain is set according to the drive voltage. That is, the proportional gain Kip and the integral gain Kii are two times (2a, 2b) or four times (4a, 4b) as the driving voltage decreases, assuming that the values when the driving voltage becomes maximum are a and b, respectively. Set as follows.

  Note that the robot 10 according to this embodiment cannot walk only by standing upright when the 1Y motor 42 and the 2Y motor 46 are driven at the predetermined voltage Vm, and can walk at low speed when driven at 2Vm. However, high-speed walking is not possible, and high-speed walking is only possible when driven at 4 Vm. FIG. 7 shows only the processing for the 1Y motor 42 and the 2Y motor 46, but the control is performed by processing similar to the processing shown in FIG. 7 except that the other electric motors are not boosted.

  In the following description, power on is executed in S10. This process will be described with reference to FIG. 4. The central controller 24 instructs the power supply controller 26 to supply a predetermined voltage Vm from the battery 28 to the motor driver 92b. When the predetermined voltage Vm commanded from the power supply controller 26 is supplied, the motor driver 92b sends a signal indicating that the power-on is completed to the central controller 24.

  Next, in S12, the servo is turned on. That is, the central controller 24 instructs the motor driver 92b to rotate the 1Y motor 42 and the like to the control origin position and then stop at that position. The motor driver 92b executes an operation according to the command, and when the operation is completed, the motor driver 92b sends a signal to the central controller 24 that the servo-on is completed (servo mechanism activation operation is completed).

  Next, in S14, the robot 10 is controlled to be in an upright posture. Specifically, after the servo-on is completed, the robot 10 is lowered from a lifter (not shown) and controlled to maintain an upright state based on the outputs of the six-axis force sensor 76 and the inclinometer 80.

  Next, in S16, a walking start command (consisting of a high-speed / low-speed walking operation mode signal) is output to the motor drivers 92a, 92b, 92c. That is, by sending an operation mode signal from the central controller 24 to the motor driver 92b, the drive voltage is increased before the start of the high-speed walking operation, while the current feedback gain of the motor driver 92 is decreased to reduce the 1Y motor 42, etc. Corresponds to high-speed rotation.

  Next, the process proceeds to S18, in which it is determined whether or not a temperature abnormality has occurred where the temperature of the booster 98 or the motor driver 92 detected by the temperature sensor 102 exceeds a predetermined value. The setting of the current feedback gain is changed in accordance with the operation mode of the walking start command output in S16, and the process proceeds to S22, where the booster 98 is turned on and boosted to 2 Vm or 4 Vm depending on the operation mode. Note that the drive voltage remains at the predetermined voltage Vm until this time.

  Next, in S24, it is determined whether or not the boosting operation of the booster 98 is normal. This is done by monitoring the output voltage of the booster 98 with A / D converters (not shown) of the motor drivers 92b and 92c and determining whether the voltage is boosted to a predetermined voltage range.

  When the result in S24 is affirmative, the process proceeds to S26, where the robot 10 starts walking, and the process proceeds to S28 and continues until the walking is finished. Next, the process proceeds to S30, where the supply voltage to the motor is stepped down to Vm in a steady state, and the process proceeds to S32, where the setting is changed to the current feedback gain corresponding to Vm. Next, the process proceeds to S34, the control is again performed to the upright posture, the process proceeds to S36, the servo is turned off (stop of the electric motor), the process proceeds to S38, and the power is turned off (voltage supply from the battery 28 is stopped).

  If the result in S18 is affirmative, or the result in S24 is negative, that is, if a temperature abnormality has occurred or if the voltage is not boosted to a predetermined voltage range, the boosting operation is not performed or is stopped. .

  FIG. 9 is a time chart showing the processing of FIG.

  As shown in the figure, the set value of the current feedback gain is changed when standing upright immediately before the start of the walking motion, and then the voltage is boosted by the booster 98. change. That is, the set value of the current feedback gain is changed before increasing the voltage of the booster 98, and is changed after decreasing the voltage. Although the control period of the left leg booster and motor driver is not shown in the figure, the same processing as that for the right leg is performed. In this way, the current feedback gain is lowered before boosting, and the current feedback gain is raised after stepping down. If this order is reversed, the motor may oscillate, so this is set in consideration of safety.

  Note that there may be a situation where the current feedback gain is lowered before the boosting is completed, but in this case, the motor torque may be insufficient. However, since the timing of switching is upright, if there is a slight torque shortage, the effect of this is considered to be small. The same applies to the second embodiment when the switching timing is a free leg. In any case, the smaller the difference in the switching timing, the better.

  As described above, in the first embodiment, joints, that is, joints of a plurality of (two) links (thigh link 30 and crus link 32) connected via a hip joint, a knee joint, and an ankle joint. At least motor drivers (driving circuits) 92a, 92b, and 92c that drive an electric motor such as the 1Y motor 42 that is supplied from a battery (power supply) 28 through a power line 90 according to an energization command are provided. The driving device for the mobile robot 10 includes boosters 98a and 98b that boost the drive voltage supplied to an electric motor such as the 1Y motor 42, and the 1Y motor 42 and the boosters 98a and 98b, and drive circuits 92b and 92c. Are arranged on the same link (thigh link 30, lower leg link 32).

More specifically, a plurality of (two) leg portions 12 including a thigh link 30 connected to the base body 14 via a hip joint and a crus link 32 connected to the thigh link 30 via a knee joint are provided. At the same time, a voltage supplied from the battery (power source) 28 is supplied to the 1Y motor (first electric motor) 42 and the 2Y motor (second electric motor) 46 that drive at least the thigh link 30 and the like in the traveling direction. In the driving device of the legged mobile robot 10 including at least motor drivers (driving circuits) 92b and 92c that are supplied and driven in accordance with a command, boosting that boosts driving voltages supplied to at least the 1Y motor 42 and the 2Y motor 46 98a, and at least the 1Y motor 42 and the like, the booster 98a and the motor driver 92b are connected to the same link (femoral link). ) It was composed as placed 3 0.

  Thereby, both a low voltage requirement considering safety and a high voltage requirement for high-speed movement can be satisfied, and thus the voltage can be supplied efficiently. That is, by providing the boosters 98a and 98b on the same link as the motor drivers 92b and 92c, the voltage of the power line 90 can be kept low, and the power line 90 connecting the battery 28 and the electric motor such as the 1Y motor 42 has a joint. When straddling, even if there is a leakage due to disconnection at the joint, there is no inconvenience. On the other hand, when a high voltage is required, the voltage is boosted by the boosters 98a and 98b, so that high-speed movement can be accommodated, and thus the voltage can be supplied efficiently.

Furthermore, the arrangement of the boosters 98a and 98b is limited to those requiring a high voltage among the electric motors, that is, the 1Y motor 42, the 2Y motor 46, the 3Y motor 48, and the like that drive the thigh link 30 and the like in the traveling direction. together when placed in them and then, is placed on the same link, such as a thigh link 30, can be supplied more efficiently voltage.

  Furthermore, since the drive voltage is all output through the booster 98 by the 1Y motor 42, the drive voltage can be kept constant even when the voltage of the battery 28 fluctuates, and the motor operation can be stabilized. . Further, by setting the drive voltage and the control voltage to the same value (Vm), the step-down device in the power supply controller 26 used in the prior art shown in FIG. 17 becomes unnecessary, and the power supply controller 26 transfers to the motor driver 92. Since the power line 90 is also a single cable, it can be reduced in weight and cost. However, since it is necessary to flow a larger amount of current as the voltage becomes lower, the power line 90 is expected to be thicker, but there is an advantage over that.

  In addition, a boost control means (S16 to S22) for controlling the boosting operation of the booster 98 according to the movement state is provided. More specifically, a walking start command (operation mode signal) is sent and driven before the high-speed walking operation is started. While the voltage is increased, the current feedback gain is decreased via the motor driver 92 so as to correspond to the high-speed rotation of the electric motor. Therefore, in addition to the above effects, the necessary voltage can be supplied without excess or deficiency. Thus, the voltage can be supplied more efficiently.

  Further, the boost control means monitors the output voltage of the booster 98 and stops the boosting operation when it is not boosted to a predetermined voltage (S24, S30). It is possible to detect a failure just by monitoring the output and take necessary measures such as stopping the movement.

  In addition, a temperature sensor 102 disposed in at least one of the booster 98 and the motor driver 92 is provided, and the boost control unit stops the boost operation when the temperature detected through the temperature sensor is equal to or higher than a predetermined temperature. (S18, S30). In addition to the effects described above, it is possible to detect a failure through temperature and to take necessary measures such as stopping movement.

  Further, it is provided with feedback control means (central controller 24, motor driver 92) for feedback control of the drive current to the target value, and the gain of current feedback control is changed according to the boosting operation of the boost control means (S20). Therefore, in addition to the above-described effects, the 2Y motor 46 and the like can be reliably driven at a necessary rotational speed.

  FIG. 10 is a flow chart similar to FIG. 7 showing the operation of the mobile robot driving apparatus according to the second embodiment of the present invention. The illustrated program is also executed by the central controller 24.

  FIG. 11 is an explanatory view similar to FIG. 8 showing characteristics such as the drive voltage set in the process of FIG. In the second embodiment, as shown in FIG. 11, the driving voltage is made different between when walking and when walking as in the first embodiment, and at 2 Vm when supporting at low speed walking and when walking at high speed, It was set to 4 Vm at the time of a free leg during high-speed walking that requires high-speed rotation. The change of the setting value of the current feedback gain is the same as in the first embodiment.

  Further, the values shown in FIG. 11 are values for the 2Y motor 46, but the same applies to the 1Y motor 42 as well, unlike the first embodiment. Further, only the processing for the 1Y motor 42 and the 2Y motor 46 is shown, but the other electric motors are also controlled by similar processing, as in the first embodiment.

  Explained below, after the same processing as in the first embodiment is performed from S100 to S104, the process proceeds to S106, a walking start signal is output to the motor driver 92 immediately before walking, and the process proceeds to S108 to start walking.

  In S110, the motor driver 92b changes the set value of the current feedback gain to boost the voltage to 2Vm, which is the set voltage at the time of the upright start, according to the walking start signal, and in S112, the booster 98a is turned on to boost the voltage to 2Vm. Next, the process proceeds to S114 to determine whether or not the pressure has been increased. If the determination is affirmative, the process proceeds to S116 to determine whether or not a temperature abnormality has occurred.

Proceeds to S118 if negative in S116, the update of the operation mode, i.e., the operation mode of the motor driver 92b shown in FIG. 11, and sequentially output to 92c, the process proceeds to S 120, the characteristic shown in FIG. 11 in the motor driver 92b Based on this, it is determined whether or not high speed driving is required. When the result in S120 is affirmative, the program proceeds to S122, in which the current feedback gain is changed to the set value at the time of high-speed driving based on the characteristics of FIG. 11 via the motor drivers 92b and 92c. Boost to 4Vm. Next, in S126, it is determined again whether or not the pressure has been increased.

  On the other hand, when the result in S120 is negative, the process proceeds to S128, and low speed driving is sufficient. Therefore, the voltage is stepped down to 2Vm via the motor driver 92b based on the characteristics of FIG. 11, and then the process proceeds to S130 to obtain a current feedback gain corresponding to 2Vm. Change the setting value.

  Next, the process proceeds to S132, where it is determined whether or not walking is completed. As long as the result is negative, the above process is repeated. On the other hand, if the result is affirmative, the process proceeds to S134 and the pressure is lowered to the steady state Vm. The setting value is changed to a corresponding value, and the process ends after the processing from S138 to S142, as in the first embodiment. If the result in S114 is negative, the result in S116 is affirmative, or the result in S126 is negative, the process proceeds to S134.

  FIG. 12 is a time chart showing the processing of FIG.

  When the robot 10 starts walking from an upright state, the first leg to be drawn is a free leg, and the opposite leg is a support leg. High-speed rotation is required when the right leg, which is a swing leg, is moved forward greatly during high-speed walking, and this period is shown in black.

  Normally, high-speed rotation is necessary during swinging legs. In other words, it is a free leg, and it is sufficient if the voltage is high only at the moment of high-speed rotation. Therefore, in the second embodiment, the timing of step-up to 4 Vm or step-down from 4 Vm is set at the free leg, and the voltage is increased only at that moment. I tried to control it.

  As described above, the mobile robot driving apparatus according to the second embodiment can search at a table value set in advance according to the moving state, that is, the characteristic shown in FIG. In addition to the above-described effects, the booster 98 is configured to control the boosting operation, so that it becomes easy to supply the necessary voltage without excess or deficiency, and the voltage can be supplied more efficiently.

  Furthermore, by setting the timing of stepping up to 4Vm or stepping down from 4Vm at the time of a free leg with little risk of falling, it is assumed that the 1Y motor 42 etc. oscillates due to a deviation in the setting of the drive voltage and current feedback gain. However, the possibility of falling can be reduced.

  The remaining configuration and effects are not different from those of the first embodiment.

  FIG. 13 is a flow chart similar to FIG. 7 showing the operation of the mobile robot driving apparatus according to the third embodiment of the present invention. The illustrated program is also executed by the central controller 24.

  FIG. 14 is an explanatory diagram similar to FIG. 8 or FIG. 11, showing the voltage change characteristics of the third embodiment for the 2Y motor 46. In the third embodiment, as shown in FIG. 14, the voltage level and the current feedback gain corresponding to the required joint angular velocity estimated from the operation of the robot 10, that is, the angular velocity ω [rad / second] of the knee joint are set. Values are prepared in advance as table values, enabling fine control.

  The description will focus on the differences from the first and second embodiments. After performing the same processing as in the first and second embodiments from S200 to S210, the process proceeds to S212, where the joint angular velocity ω is updated. That is, after the start of walking, the central controller 24 sequentially outputs the angular velocity ω of the knee joint to the motor driver 92b between ω1 and ω4 according to the characteristics shown in FIG. The values shown in FIG. 14 are values for the 2Y motor 46, but the same applies to the 1Y motor 42.

  Next, when it is determined that there is a change in the joint angular velocity ω in S214, the setting of the current feedback gain is changed via the motor driver 92b in S216, and the setting voltage, that is, the output voltage of the booster 98a is changed in S218. It is determined whether or not the voltage has been changed in S220, and the above-described processing is repeated until it is determined in S222 that walking has been completed. The remaining processing is the same as that in the first and second embodiments. Although only the processes for the 1Y motor 42 and the 2Y motor 46 are illustrated, the other electric motors are also controlled by similar processes as in the first and second embodiments.

  FIG. 15 is a time chart showing the processing of FIG.

  As described above, also in the mobile robot driving apparatus according to the third embodiment, the table value set in advance according to the movement state, that is, the angular velocity of the knee joint estimated from the operation of the robot 10 as shown in FIG. Based on the above, the voltage level and current feedback gain corresponding to it are searched to control the boosting operation of the booster 98a. In addition to the above effects, it becomes easy to supply the necessary voltage without excess or deficiency, The voltage can be supplied more efficiently.

  The remaining configuration and effects are not different from those of the first embodiment.

  FIG. 16 is a block diagram of a driving apparatus similar to that of FIG. 4, showing a fourth embodiment of the driving apparatus for the mobile robot according to the present invention.

In the fourth embodiment, the booster 98a, 98b while interposed in the power line 90 were composed as provided bypass passage 90 b for bypassing the booster 98a, a 98b to the power line 90. Blocking diode 104 is installed in the bypass passage 90 b.

  Further, the output voltage of the battery 28 is set to 2 Vm, and the voltage is stepped down to Vm by the step-down device 26 a of the power supply controller 26. In other words, in addition to the power line 90, the second power line 106 is provided, and the drive voltage 2 Vm is supplied through the power line 90, and the stepped-down control voltage Vm is supplied through the second power line 106.

  Since the fourth embodiment is configured as described above, there is a disadvantage that the backflow prevention diode 104 is required in the bypass path, but the power loss can be reduced as compared with the case where the booster 98 is used. The diode 104 can be replaced with an FET.

  In the first to fourth embodiments, as described above, a plurality of links (thigh link 30 and crus link 32) connected via joints, and electric motors (1Y motor 42, 2Y motor 46) disposed in the joints. Etc.), a power source (battery) 28 disposed in a portion other than the plurality of links, a power line 90 connecting the power source and the electric motor, and a voltage supplied from the power source through the power line as an energization command Accordingly, the driving device of the mobile robot 10 including at least a driving circuit (motor driver 92) that supplies and drives the electric motor includes a booster 98 that boosts the driving voltage supplied to the electric motor, and The electric motor, the booster and the drive circuit are arranged on the same link (thigh link 30 or crus link 32).

Further, the substrate 14, a plurality of legs 12 formed of the shank link 32 which is connected through the knee joint to the thigh link 30 connected via the hip joints to the body said thigh link, before Symbol thigh link a first electric motor for driving the traveling direction (1Y motor 42), and a second electric motor for driving the front Symbol shank link to said traveling direction (2Y motor 46), the portion other than the thigh link and the crus link A power source (battery) 28 disposed in the power source, a power line 90 connecting the power source and the first and second electric motors, and a voltage supplied from the power source through the power line in response to an energization command, In the driving device of the mobile robot 10 including at least a driving circuit (motor driver 92b) that supplies and drives the second electric motor, the first and second electric motors (1Y motor 4) A booster 98a for boosting the driving voltage supplied to the 2Y motor 46), the boost control means (S16 to control the boosting operation of the booster according to the moving status S22; S106 from S130; S206 from S218) and provided with a, as construction of arranging the first, second electric motor (1Y motor 42,2Y motor 46) and the booster 98a and the front asked dynamic circuits and a (motor driver 92b) on the thigh link 30 did.

  Further, as shown in the fourth embodiment, the booster 98 is inserted in the power line 90, and a bypass path 90a for bypassing the booster 98 is provided in the power line 90.

  Further, the boost control means is configured to search a table value set in advance according to the movement status and control the boost operation of the booster 98 (S16 to S22; S106 to S130; S206 to S220). .

  The boost control means is configured to monitor the output voltage of the booster 98 and stop the boosting operation when the voltage is not boosted to a predetermined voltage (S24, S30; S114, S134; S220, S224).

  In addition, a temperature sensor disposed in at least one of the booster 98 and the drive circuit (motor driver 92) is provided, and the boost control means has a temperature detected via the temperature sensor equal to or higher than a predetermined temperature. The boosting operation is stopped (S18, S30; S116, S134; S210, S224).

  In addition, feedback control means (S20; S122, S130; S216, S226) for feedback control of the drive current to the target value is provided, and the feedback control means is configured to provide a feedback control gain (in accordance with the boost operation of the boost control means ( (Current feedback gain) is changed (S20; S122, S130; S216, S226).

  In the above description, only the leg portion 12 is shown, but the same applies to the arm portion 20, and a booster may be provided for the motor driver straddling the joint, and they may be arranged on the same link.

  In addition, although two electric motors are controlled by one motor driver 92, the number of electric motors controlled by the motor driver 92 is not limited thereto, and the CPU processing capacity and weight of the motor driver 92 are not limited thereto. It is determined in consideration of various factors such as size and complexity of wiring. For example, if the motor driver 92 is very light and small, it is possible to control one electric motor with one motor driver. In addition, if the processing capability of the CPU is sufficiently high, four electric motors can be controlled by one motor driver.

  Further, the booster 98 is disposed in both the motor driver 92b for controlling the 1Y motor 42 and the 2Y motor 46, and the motor driver 92c for controlling the 3Y motor 48 and the 3X motor 50. However, the 1Y motor 42 and the 2Y motor 46 are controlled. The booster 98 may be disposed only in the motor driver 92b.

Further, the current feedback gain is calculated from the drive voltage. However, since the motor speed and the drive voltage are in a proportional relationship, the current feedback gain may be calculated from the motor speed as follows.
Ki = C / N (N: motor speed, C: constant)

  Further, although the number of operation modes is 3 or 4 in FIGS. 8, 11 and 14, it is not limited to this. Thus, it is thought that up to several patterns are realistic.

  In addition, the drive voltage is changed according to the output of the central controller 24, but it may be determined by judging whether to land or leave from the output of the six-axis force sensor 76.

  In addition, a mobile robot, particularly a legged mobile robot, has been shown as an example of a mobile body. However, the present invention is not limited to this, and includes a plurality of links connected via joints and is arranged at the joints. The present invention is applicable to any mobile robot that supplies a voltage from a power source disposed in a portion other than the joint to the electric motor.

It is a front view of the mobile robot which the drive device of the mobile robot which concerns on 1st Example of this invention makes object. It is a side view of the robot shown in FIG. It is explanatory drawing which shows the robot shown in FIG. 1 with a skeleton. FIG. 3 is a block diagram showing supply of drive voltage from the battery shown in FIG. 2 to the electric motor. FIG. 5 is a side view of a robot similar to FIG. 2, specifically showing the arrangement of the robot such as the motor driver shown in FIG. 4. It is a block diagram which shows the feedback loop of electric motor control shown in FIG. It is a flowchart which shows operation | movement of the drive device of the mobile robot which concerns on 1st Example of this invention. It is explanatory drawing which shows the characteristic of the drive voltage and electric current feedback gain which are set by the process shown in FIG. It is a time chart which shows the process shown in FIG. FIG. 8 is a flow chart similar to FIG. 7 showing the operation of the mobile robot drive device according to the second embodiment of the present invention. FIG. It is explanatory drawing which shows the characteristic of the drive voltage and electric current feedback gain which are set by the process shown in FIG. It is a time chart which shows the process shown in FIG. FIG. 8 is a flow chart similar to FIG. 7 showing the operation of the mobile robot drive device according to the third embodiment of the present invention. FIG. It is explanatory drawing which shows the characteristic of the drive voltage and electric current feedback gain which are set by the process shown in FIG. It is a time chart which shows the process shown in FIG. FIG. 9 is a block diagram of a driving device similar to FIG. 4, showing a fourth embodiment of the driving device for the mobile robot according to the present invention. It is a block diagram of the drive device similar to FIG. 4 which shows the drive device of the mobile robot which concerns on a prior art.

Explanation of symbols

  10 legged mobile robot (mobile robot), 12 legs, 14 base, 20 arms, 24 central controller, 26 power controller, 28 battery (power), 30 thigh link, 32 lower leg link, 40 1Z motor (electric) Motor), 42 1Y motor (electric motor), 44 1X motor (electric motor), 462 2Y motor (electric motor), 48 3Y motor (electric motor), 50 3X motor (electric motor), 90 power line, 92 motor driver ( Drive circuit), 96 signal lines, 98 booster, 102 temperature sensor, 104 backflow prevention diode, 106 second power line

Claims (6)

A substrate, and a plurality of legs comprising a shank link connected via a knee joint to the femoral link thigh link connected via the hip joints to the substrate, driving the front Symbol thigh link in the traveling direction a first electric motor, prior SL and a second electric motor for driving the lower leg link in the traveling direction, and a power source arranged on a site other than the thigh link and the shank link, said first and said power supply, second And a drive circuit for supplying and driving a voltage supplied from the power source through the power line in response to an energization command to the first and second electric motors. in the driving device, the first, the booster that boosts the driving voltage supplied to the second electric motor, provided with a step-up control means for controlling the boosting operation of the booster in response to the moving condition, the 1, the driving device of a mobile robot and a front SL drive circuit a second electric motor and the booster, characterized in that arranged on the thigh link. While interposed said booster to said power line, the driving device of a mobile robot according to claim 1 Symbol mounting, characterized in that a bypass passage bypassing the booster to the power line. 3. The driving apparatus for a mobile robot according to claim 1, wherein the boosting control unit searches a table value set in advance according to the moving state and controls the boosting operation of the booster. The boosting control unit monitors the output voltage of the booster, when not boosted to a predetermined voltage, the driving of the mobile robot according to any of claims 1 to 3, characterized in that to stop the boosting operation apparatus. A temperature sensor disposed in at least one of the booster and the drive circuit is provided, and the boost control unit stops the boost operation when a temperature detected through the temperature sensor is equal to or higher than a predetermined temperature. driving device for a mobile robot according to any of claims 1 4, characterized in that The driving current provided with a feedback control means for feedback control to the target value, the feedback control means of claims 1 to 5, characterized in that changing the gain of the feedback control in accordance with the boosting operation of the boosting control means A drive device for a mobile robot according to any one of the above.

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